Attachment apparatus for material handling vehicles, and material handling vehicles

ABSTRACT

In a materials handling vehicle with lift arms, a cradle is pivotally mounted on the lift arms and a material handling bucket is pivotally mounted on the cradle. The bucket can be locked to the cradle to enable normal tipping of the bucket on the lift arms by the tipping ram, or the cradle can be locked to the lift arms to enable tipping of the bucket on the cradle to enable the tipping height to be increased without increasing the overall height of the vehicle. There may be an acceleration linkage between the tipping ram and bucket to obviate the need for using an extra long tipping ram.

United States Patent Shepherd [451 Sept. 12, 1972 [54] ATTACHMENT APPARATUS FOR MATERIAL HANDLING VEHICLES, AND MATERIAL HANDLING VEHICLES [72] Inventor: Edward Shepherd, 28 Sandyacres,

Leeds, England 221 Filed: Sept. 9,1970

21 Appl.No.: 70,720

[52] US. Cl. ..2l4/774, 214/776, 214/780 [5 l] Int. Cl. ..B66f 9/00 [58] Field of Search ..214/773, 780, 774, 775, 776,

[56] References Cited UNITED STATES PATENTS 3,521,783 7/ 1970 McAdams ..214/780 3,385,460 5/1968 Wagner ..214/780 3/1949 Beyerstedt ..2l4/774 9/1970 Chant ..2l4/774 [57] ABSTRACT In a materials handling vehicle with lift arms, a cradle is pivotally mounted on the lift arms and a material handling bucket is pivotally mounted on the cradle. The bucket can be locked to the cradle to enable normal tipping of the bucket on the lift arms by the tipping ram, or the cradle can be locked to the lift arms to enable tipping of the bucket on the cradle to enable the tipping height to be increased without increasing the overall height of the vehicle. There may be an acceleration linkage between the tipping ram and bucket to obviate the need for using an extra long tipping ram.

2 Claims, 4 Drawing Figures PATENTED EP z I912 3.690.494

SM] 1 OF 3 EDWARD SHEPHERD PATENTEDsEP 12 m2 SHEET 2 UF 3 WQNTQ Q EDWARD SHEPHERD BY F/GZA I LbcAe PATENTED 2 I97? I 3 690.494

sumanrs EDWARD SHEPHERD ATTACHMENT APPARATUS FOR MATERIAL HANDLING VEHICLES, AND MATERIAL HANDLING VEHICLES This invention relates to attachment apparatus for vehicles of the type which are designed to handle materials such as soil, aggregate, sand, timber, stones etc., and have jib type lifting arms on which the attachment apparatus is mounted, and the invention also relates to vehicles equipped with such apparatus.

The most common vehicle of this type is a shovel loader which has a shovel or bucket at the end of the lifting arms which can be pivoted on the arms to effect a scooping up or tipping of batches of material. The shovel or bucket may be replaced by a grab where the vehicle is for handling, for example, timber logs or the like.

The lift arms are raised and lowered by hydraulic lifting ram means and the bucket is pivoted on the arms by means of tilting, hydraulic ram means, such ram means being supplied from a pump through valve means under the control of the operator.

A disadvantage of known attachment apparatus, i.e., the bucket, in the known vehicles is that the point of pivoting of the bucket on the lift arm is so located as to restrict the tipping height of the bucket, and to locate the axis of tipping at a more convenient location would result in an increase in the tendency of the vehicle to tip over when the bucket is loaded, which is not permissible.

An object of the present invention is to provide attachment apparatus for a vehicle of the type designed to handle materials, which will enable the tipping height of the vehicle to be increased, without necessarir ly decreasing the working range of the vehicle.

According to the invention there is provided attachment apparatus for a vehicle of the kind designed to handle materials comprising a bucket, support means on which the bucket can be mounted for tipping movement, said support means being adapted to be pivotally mounted on the lift arms on the pivots which normally accommodate the vehicle bucket, and locking means operable to lock the bucket to the support means or the support means to the lift arms so that the bucket in use, can be pivoted with the support means about the normal axis of pivoting or about an axis spaced from such normal axis which ensures tipping of the bucket at a higher level.

The locking means is preferably designed such that in use, the bucket is either held securely to the support means or the support means is held to the lift arms.

The locking means is preferably a locking cylinder which is secured to the support means and which is adapted for hydraulic connection to the lift ram means of the vehicle through a selector valve operable by the vehicle operator. The selector valve may be associated with the control lever of the vehicle main valve so that by moving the control lever in a direction transverse to its normal direction of operation for the lift ram means and tilting ram means, the selector valve is actuated to cause the support means to become locked to the lift arms and the bucket can tilt about the pivot which effectively increases the tipping height of the vehicle. The support means will preferably. in use be locked to the lift arms only when such arms are raised to ensure that the tipping load of the vehicle is not decreased.

Preferably there is a linkage means between the bucket and support means, which linkage means is for connection to the tilting ram means so that, when the support means is locked to the lift arms, and the tilting ram means actuated, the bucket tipping movement is amplified by the linkage in relation to the movement of the tilting ram means. This provides that it is not necessary to have exceptionally long stroke tilting ram means, and also that the tilting ram means on a conventional bucket loader can be used with the apparatus of the invention.

Embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings wherein:

FIG. 1 shows in side view the lift arms and bucket attachment of a conventional shovel loader;

FIG. 2 shows the lift arms of the same shovel loader of FIG. 1 but with the bucket replaced by attachment apparatus according to a first embodiment of the invention;

FIG. 2A is an enlarged view showing details of the locking arrangement;

FIG. 3 shows in two positions apparatus according to a second embodiment of the invention, the upper position being shown in chain dotted lines and the lower portion in full lines.

In FIGS. 1 and 2 of the drawings, the associated hydraulic system is shown diagrammatically, and the arms and attachments are shown in full lines in the lowermost position and in dotted lines in the uppermost position.

Referring firstly to FIGS. 1 and 2 of the drawings, the vehicle lift arms are indicated by 10, being pivotally mounted on the vehicle at 12 and adapted to be raised and lowered by lift rams 14. The tilting mechanism comprises a linkage made up of lever 16 pivoted to the link arm 10 at 18 and having one arm pivoted to one end of a link 20 the other end of which is pivoted to the vehicle frame. The other end of lever 16 is pivotally connected to the end of a tilting ram 22 having its piston pivotally connected to the rear of the bucket or shovel 24. The bucket 24, in the known arrangement, is pivotally mounted on the ends of arms 10 at pivots 26.

The rams 12, 22 are supplied in conventional manner, with hydraulic fluid under pressure from a pump 28 driven by the vehicle prime mover through a main control valve 30 and manually operable valves 32 each having a control lever 34.

The above described arrangement is well known and reference to FIG. 1 shows clearly that the bucket 24 in each position is constrained to pivot about the pivotal mounting 26 to effect tipping of its contents. In the upper position it will be observed that the front edge of the bucket 24 moves downwards as the contents thereof are tipped out. This is a disadvantage of this known arrangement, because by virtue of the downward movement of the bucket. front edge, the effective tipping height is reduced. If the bucket were pivoted on the other hand about such front outer edge, then an increased tipping height would be achieved. Merely to mount thebucket 24 on the lift arms 10 for pivoting movement about the front edge would not be permissible however, as this would decrease the tipping load when the bucket is tipping in the lower position.

This invention aims at providing a conversion apparatus to enable the efiective maximum tipping height to be increased, whilst enabling the vehicle to operate at its rated tipping load when tipping in the lower position.

The arrangement of the lift arms fitted with the conversion apparatus according to the first embodiment of the invention is shown in FIG. 2. Firstly the bucket 24 is removed and a pair of locking segment plates 36 are rigidly secured to the lift arms 10 as shown. In place of bucket 24 is an assembly comprising support means in the form of a pair of bell crank pivot levers 38 and a bucket 40 which is pivotally mounted at its front edge on the lever 38 for pivotal movement about axis 42. Mounted on the support means by a brace 43 which extends between the arms of bell crank 38 is a locking device in the form of an actuator cylinder 44 which is positionable either to lock the bucket 40 to the support means for tipping in the lower position, or to lock the support means to the lift arms 10 for tipping in the upper position. The cylinder 44 is arranged so that it is not possible to lock the bucket 40, support means and lift arms 10 together. The bucket 40, as shown in FIGS. 2 and 2A, is provided with teeth 39 which are adapted to be engaged by the tip of a movable piston rod 41 which protrudes from actuator cylinder 44. The actuator piston of the cylinder is by a helical spring 45 biassed so that in the normal position the bucket 40 is locked to the support means and the support means is mounted for pivotal movement at pivots 26 (i.e., the normal pivots for the bucket 40), and in such normal position the loader functions in the same manner in which it would if it simply had the bucket arrangement of FIG. 1; that is to say, the working range of the loader is in no way reduced, when the actuator 44 is in the normal position. When the actuator 44 is moved to the high tipping position however, the support means can be locked to the lift arms 10 by causing the piston of the actuator cylinder to engage the teeth of plate 36 and in such position actuation of the tilting rams causes the bucket 40 to tilt about the axis 42 which is spaced from pivots 26 and, as explained previously, increases the tipping height of the loader considerably.

In the example shown in FIG. 2 the attachment apparatus can be easily connected to an existing loader and the actuator 44 can be coupled, through a valve 46 to the lift side of the main lift rams 14.

The valve 46 is positioned to be actuated by a control lever 34 upon displacement of such lever 34 in a direction transverse to its direction of movement for adjusting its associated lift or tilting ram, to allow the pressure in the lift rams 14 to be transmitted to the actuator cylinder 44 and cause actuation of same and hence locking of the support means to the lift arms.

. In the embodiment shown in FIG. 3, some of the parts of the apparatus and shovel loader shown in FIG. 2 have been omitted for clarity, but apart from the differences to be described, the FIG. 3 arrangement has all of the FIG. 2 embodiment. As in the FIG. 2 embodiment, the apparatus includes a bucket 40, support means in the form of arms 38 which are pivotally mounted on lift arms 10, the bucket 40 being pivotally mounted on the arms 38 at 42. As in the embodiment of FIG. 2 there is locking means to lock either the support arms 38 to the bucket 40 (normal operation) or the support arms 38 (maximum tipping position) to the lift arms 10, in which case the bucket can be pivoted on pivots 42 so that the maximum tipping height of the vehicle is increased.

Tipping in the FIG. 2 arrangement is by connecting the tilting rams means in the form of two rams 22 directly to the bucket 40, but in this embodiment the rams 22 are coupled to an acceleration linkage means connected between the bucket 40 and support arms 38 so that movements of the tilting rams 22 are amplified at the bucket 40, when the support arms 38 are locked to the lift arms 10. The acceleration linkage means comprises, at each side of bucket 40, a long link 50 and a short link 52 pivotally connected end to end, the other ends being respectively pivotally connected to the support arms 38 and bucket 40. The tilting rams 22 are respectively pivotally connected to the long links 50 at points intermediate to their ends. The efiect of extending the tilting rams 22 by the relatively short distance X in FIG. 2 effects a complete tipping of the bucket 40 about pivots 42. This provides the advantage that it is not necessary to have tilting rams 22 with an exceptionally long stroke to effect tipping in the upper position (top part of FIG. 3) and so the attachment ap paratus can be attached to a conventional shovel loader with the minimum of expense and, as in the FIG. 2 embodiment, the operating range of the bucket is not reduced.

Modifications may be made to the linkage provided that the desired amplification of the tilting ram movement is obtained.

A substantial advantage of each embodiment of this invention will be apparent. In a simple and inexpensive manner it is possible to increase the tipping height of a shovel loader without detracting from the performance of the vehicle. It is simple because it requires only the addition of valve 46, the coupling of same to rams l4 and the replacing of the bucket 24 by the assembly shown in FIG. 2 or 3. It is cheap because it requires only replacement of several relatively minor parts of the vehicle.

Many modifications in either embodiment may be made without departing from the scope of the invention; for example the bucket could be replaced by a grab for timber or scrap metal in it is intended that the expression bucket as used herein, should cover this alternative, the support means could take other forms and the locking device may be any of a number of possible alternatives.

I claim:

l. A vehicle of the kind designed to handle materials and loads, said vehicle having a. lift arms;

b. hydraulic lift ram means for raising and lowering said lift arms;

c. bucket support means mounted on the outer ends of said lift arm means for pivotal movement about a pivot axis;

(1. a bucket pivotally mounted on said support means for tipping movement thereon about an axis which is spaced outwardly from said first axis;

e. hydraulic tipping ram means for tipping said bucket; and

5 6 f. two position locking means operable in one of the hydraulic lift ram means so as to be capable of positions to lock the bucket to the support means movement to the other position only when the so that the bucket and support means can be hydraulic lift ram means is pressurized and hence pivoted by said hydraulic ram means as a unit on the lift arms are raised.

the lift arms about the first axis, and in th th r f 5 2. A vehicle according to claim 1, wherein the selecth iti n t l k th p rt means t th lift tor valve is associated with the control lever of the vehia so that th b k t can b ti d b id cle main valve for the lift ram means so that by moving h d li ram means on th support means about the control lever in a direction transverse to its normal Said Second axis permitting the discharge of the direction of operation for the lift ram means, the selecb k tl d atagl-eatelheight than is permitted by 10 tor valve is actuated to cause the support means to pivoting about said fi t axis, said loCking means become locked to the lift arms and the bucket can tilt comprising a hydraulic locking cylinder which is abfmt the P which effectively increases the pp normally in said one position but which is hydraulihelght of the vehlclecally connected through a selector valve with the 

1. A vehicle of the kind designed to handle materials and loads, said vehicle having a. lift arms; b. hydraulic lift ram means for raising and lowering said lift arms; c. bucket support means mounted on the outer ends of said lift arm means for pivotal movement about a pivot axis; d. a bucket pivotally mounted on said support means for tipping movement thereon about an axis which is spaced outwardly from said first axis; e. hydraulic tipping ram means for tipping said bucket; and f. two position locking means operable in one of the positions to lock the bucket to the support means so that the bucket and support means can be pivoted by said hydraulic ram means as a unit on the lift arms about the first axis, and in the other of the positions to lock the support means to the lift arms so that the bucket can be tipped by said hydraulic ram means on the support means about said second axis permitting the discharge of the bucket load at a greater height than is permitted by pivoting about said first axis, said locking means comprising a hydraulic locking cylinder which is normally in said one position but which is hydraulically connected through a selector valve with the hydraulic lift ram means so as to be capable of movement to the other position only when the hydraulic lift ram means is pressurized and hence the lift arms are raised.
 2. A vehicle according to claim 1, wherein the selector valve is associated with the control lever of the vehicle main valve for the lift ram means so that by moving the control lever in a direction transverse to its normal direction of operation for the lift ram means, the selector valve is actuated to cause the support means to become locked to the lift arms and the bucket can tilt about the pivot which effectively increases the tipping height of the vehicle. 